In one of our Biology lessons, we identified two plant
species within a given area in our campus field and used
chi-square analysis to see whether the distribution of
two species were dependent on each other or not. If
References
Brent Cornell. (n.d.). Retrieved from https://ib.bioninja.
com.au/standard-level/topic-4-ecology/41-species-
communities-and/chi-squared-test.html
Using Chi-Square Statistic in Research. (n.d.).
Retrieved from https://www.statisticssolutions.com/
using-chi-square-statistic-in-research/
Merve AKKUŞ
11- A
THE CLAPPER 2018 - 2019
65
they are found in the same habitat, this shows a positive
association between them and there is a negative
association if they are not found in the same habitat.
A negative association between them shows that the
two species are not interacting and their distribution is
independent of one another.
Quadrat sampling is the method we used to obtain
observed values to check the presence of the two species
in a given area which was the garden of our school. We
worked with plant species as quadrat sampling is not
an effective method for moving organisms. A quadrat
is a square frame of 1 m2 and we placed our quadrats
in a 400 m2 area randomly. We repeated the sampling
process 15 times to obtain reliable results. For each
quadrat, we determined the presence or absence of each
plant species. This allowed us to compare the number of
quadrats where both species were present with the total
number of quadrats. The application of the chi-square
test showed us that there is no statistically significant
association between the two species that we chose,
which means their distribution is independent of each
other.